the stress test only really tests the GPU. For example, I get about 70 fps on the stress test with my current setup and settings..

In the actual CS:S game, I get about 60-70 fps too, just walking around.. however, throw a few people firing, and it drops down to 40-50.. When we have the whole team rushing, against the other team that predicted our rush, I've seen it drop down to 15 fps!! This is like 8 CT vs 8 T's in the same room, all firing, and grenades and smokes flying all over the place... I'm now happy that I'm getting my 2.6HT replaced with a 3.4, cause that should help out during those CPU bound times.. (I have 1.5 gigs of ram so there's no HD paging issues)

So overall, I think its about where it should be.. I predict in the HL2 single player, throw in a 4 or 5 enemies/NPC's fighting on the screen, in a real game env, we'll probably see fps close to half from avg.. A reasonable balance between CPU and GPU loading...